Survival of Escherichia coli from freeze–thaw damage: a theoretical and practical study

1974 ◽  
Vol 20 (5) ◽  
pp. 671-681 ◽  
Author(s):  
Peter H. Calcott ◽  
Robert A. MacLeod
Keyword(s):  
Escherichia Coli ◽  
Cooling Rate ◽  
Tween 80 ◽  
Cell Types ◽  
Distilled Water ◽  
Cell Water ◽  
Survival Curves ◽  
Cooling Rates ◽  
Freeze Thaw ◽  
Ionic Detergent

The effect of cooling and warming rates on the cryosurvival of chemostat populations of Escherichia coli was investigated. Survival curves were obtained which were similar in shape to those obtained by others for other cell types, with saline always a more lethal environment than distilled water.For organisms frozen in either distilled water or saline, as the cooling rate was increased survival increased to a maximum at 6 C/min, decreased to a minimum at 100 C/min, and then continued to increase as the cooling rate was increased to ultrarapid rates (about 6000 C/min). At these ultrarapid rates of cooling but not at lower rates, increasing the rate of warming enhanced survival; slow warming rates were detrimental to survival and eliminated the increase in survival associated with these cooling rates. Solution of a theoretical equation predicted that supercooling of cell water, and thus the likelihood of internal freezing, should increase as the cooling rate was increased from 3.5 to 350 C/min. This increase in probability of internal freezing was paralleled by a decrease in viability of cells as the cooling rate was increased from 6 to 100 C/min.The effectiveness of three protectants was investigated over the whole cooling rate range. Glycerol or sucrose added to suspensions of cells in distilled water protected over the whole range; but at lower cooling rates (less than 6 C/min) they did so with an altered stoichiometry. Sucrose protected organisms frozen in saline and Tween 80, a non-ionic detergent, protected organisms frozen either in saline or distilled water from rapid or ultrarapid cooling only. The evidence supports a two-factor hypothesis to explain cryoinjury.

The survival of Escherichia coli from freeze–thaw damage: permeability barrier damage and viability

1975 ◽  
Vol 21 (11) ◽  
pp. 1724-1732 ◽  
Author(s):  
Peter H. Calcott ◽  
Robert A. MacLeod
Keyword(s):  
Escherichia Coli ◽  
Cooling Rate ◽  
Permeability Barrier ◽  
Freezing And Thawing ◽  
Slow Cooling ◽  
Cooling Rates ◽  
Rate Range ◽  
Permeability Damage ◽  
Extent Of Damage ◽  
Glucose 6 Phosphate Dehydrogenase

The effect of cooling rate and subsequent warming rate on survival of lactose-limited Escherichia coli was investigated. As previously reported, in the slow cooling rate range, a peak of survival was noted at 8 °C/min with survival decreasing as the cooling rate was increased or decreased from this value. Minimal survival was noted at 100 °C/min; increasing the cooling rate above 100 °C/min increased survival. At cooling rates greater than 200 °C/min, the survival became dependent on subsequent warming rates.Permeability damage, as measured by release of UV-absorbing material, potassium and β-galactosidase, and increased accessibility of glucose-6-phosphate dehydrogenase to its substrates, was dependent on the cooling rate when cells were frozen in either water or saline. For cooling rates less than about 8 °C/min, there was minimal permeability damage to cells frozen in water. However, at rates greater than this value, damage and viability were related; the lower the viability the more the damage to the permeability barrier. The relationship was strengthened by the observations that protectants which increased survival reduced damage as well and that at ultrarapid cooling rates where survivals were dependent on warming rates, the extent of damage was likewise dependent on the warming rate.Saline frozen cells were damaged by freezing and thawing more than comparable water-frozen cells over the whole cooling rate range. At cooling rates less than 8 °C/min, frozen in water, permeability damage of cells frozen in saline increased as the cooling rate decreased. As the cooling rate was increased from 8 °C/min, the damage increased as viability decreased.The relevance of these findings to the two-factor hypothesis of cell death is discussed.

Improved Post-Thaw Viability and In Vitro Functionality of Peripheral Blood Hematopoietic Progenitor Cells after Cryopreservation with a Theoretically Optimized Freezing Curve.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1222-1222
Author(s):  
Marloes R. Tijssen ◽  
Henri Woelders ◽  
Ada de Vries-van Rossen ◽  
C. Ellen Van der Schoot ◽  
Carlijn Voermans ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Peripheral Blood ◽  
Cell Types ◽  
Subzero Temperature ◽  
Specific Cell ◽  
Freezing And Thawing ◽  
Cooling Rates ◽  
Cd34 Cells ◽  
Non Linear ◽  
Freezing Curve

Abstract Current methods for the cryopreservation of peripheral blood stem cell transplants (PBSCTs) have been developed empirically. Although the use of cryopreserved PBSCTs is successful and usually leads to rapid hematopoietic recovery, the freeze-thawing process is known to induce a significant amount of cell death. Furthermore, the infusion of DMSO, which is used to protect the cells against damage induced by freezing, can cause morbidity. Freezing methods may be improved by using a fundamental cryobiological approach, addressing the putative causes of cell injury during freezing and thawing. Different cell types may have different optimal cooling rates. Cooling rates above this optimum may cause ‘fast cooling damage’, e.g. by lethal intracellular ice formation, while cooling rates below the optimum may lead to ‘slow cooling damage’, These cryoinjuries relate to the osmotic changes during freezing and thawing, and the resulting fluxes of water and cryoprotectant across the cell membrane. Mathematic modeling of these osmotic events can be used to predict the optimal cooling rates for specific cell types. Woelders and Chaveiro* have developed a model that calculates the ‘compromise’ cooling rate for every subzero temperature, resulting in non-linear freezing curves. In the present study, this model was applied to predict ‘optimal’ freezing curves for PBSCTs with 10% and 5% DMSO, respectively, using values for the membrane permeability coefficients and related parameters as published earlier for cord blood HPCs. These predicted curves were tested empirically and compared to the presently used standard linear freezing curve. CD34+ selected and unselected PBSCs were cryopreserved using the standard or the new freezing curves. Post-thaw quality was evaluated by cell viability, CFU-GM formation and megakaryocyte outgrowth. With 10% DMSO, the use of the predicted optimal freezing curve compared to the currently used freezing curve resulted in increased post-thaw viability of CD34+ cells (mean±SEM; 78.4%±6.6% versus 72.0%±6.1% for unselected CD34+ cells and 92.0%±0.6% versus 83.9%±2.5% [p<0.01] for selected CD34+ cells), colony formation (40.7%±8.8% versus 30.1%±7.9% [p<0.01] for unselected CD34+ cells and 102.6%±8.0% versus 90.1%±11.9% for selected CD34+ cells), and megakaryocyte outgrowth (6.0±0.7 versus 3.9±0.6 [p<0.01] CD41+ MKs per seeded selected CD34+ cell). Also lowering the DMSO concentration to 5% resulted in improved post-thaw viability and functionality, comparable to the results obtained with 10% DMSO and the predicted optimal freezing curve. The results obtained with 5% DMSO were not improved by using the theoretically optimized freezing curve, suggesting that the cooling rate of the theoretically predicted curve for 5% DMSO may have been too high. Indeed preliminary experiments with a slightly slower non-linear freezing rate suggest that further improvement is possible. Our results indicate that the current cryopreservation method for PBSCT can be improved by applying theoretically optimized freezing curves. Infusion of less DMSO and more viable cells will likely improve the outcome of PBSCT. * Woelders and Chaveiro, Cryobiology 2004, 49; 258–271

The survival of Escherichia coli from freeze–thaw damage: the relative importance of wall and membrane damage

1975 ◽  
Vol 21 (12) ◽  
pp. 1960-1968 ◽  
Author(s):  
P. H. Calcott ◽  
R. A. MacLeod
Keyword(s):  
Escherichia Coli ◽  
Cell Survival ◽  
Membrane Damage ◽  
Tween 80 ◽  
Relative Importance ◽  
Freezing And Thawing ◽  
Freeze Thaw

When Escherichia coli is frozen rapidly in saline and thawed slowly, survival is very low; however, the inclusion of 3% glycerol or 1% Tween 80 in the saline freezing menstruum results in near complete survival. The release of material from, and penetration of, substances into the cell indicate that both membrane and wall damage occur during freezing and thawing. Glycerol, under these conditions, is able to reduce severely both the damage to the wall and membrane, whereas Tween 80 prevents only membrane damage. This indicates that freezing and thawing in saline results in membrane damage which is lethal to the cell whereas wall damage which occurs is not detrimental to cell survival.

Survival of Escherichia coli from freeze–thaw damage: influence of nutritional status and growth rate

1974 ◽  
Vol 20 (5) ◽  
pp. 683-689 ◽  
Author(s):  
Peter H. Calcott ◽  
Robert A. MacLeod
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Nutritional Status ◽  
Cooling Rate ◽  
Growth Rates ◽  
Upward Trend ◽  
Rate Range ◽  
Carbon And Nitrogen ◽  
Freeze Thaw

The influence of nutritional status and growth rate on the cryosurvival of Escherichia coli was investigated. Organisms grown at rates between 0.1 and 0.6 h−1, under carbon- or nitrogen-limiting conditions all showed a basically similar cooling rate – survival profile; a peak of survival was noted in the lower cooling rate range (less than 100 C/min), a trough of minimum survival at 100 C/min, and increased survival as the cooling rate was increased to ultrarapid rates. Carbon-limited organisms showed a shift of the peak from 6 C/min for slowly grown organisms (D = 0.11) to 40 C/min at higher growth rates (D = 0.60 h−1); their survival at these peaks also showed a slightly upward trend. Nitrogen-limited organisms showed a similar trend of a shifting of the peak of survival. However, as the growth rate was increased, survival at this peak, and at other regions, decreased. For carbon-limited organisms, above 100 C/min, survival was growth rate independent, unlike nitrogen-limited organisms, which exhibited lower survivals as the cooling rate was increased in the ultrarapid range. The survival of both carbon-and nitrogen-limited organisms at the peak of survival showed a correlation with their carbohydrate and protein contents. The relevance of these findings is discussed.

The effect of cooling rate on crystallization behavior and tensile properties of CF/PEEK composites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Guangming Dai ◽  
Lihua Zhan ◽  
Chenglong Guan ◽  
Minghui Huang
Keyword(s):  
Cooling Rate ◽  
Crystallization Temperature ◽  
Crystallization Behavior ◽  
Crystalline Polymer ◽  
Scanning Calorimetry ◽  
Nonisothermal Crystallization ◽  
Cooling Rates ◽  
Control Range ◽  
Temperature Range ◽  
Transverse Tensile

Abstract In this study, the differential scanning calorimetry (DSC) tests were performed to measure the nonisothermal crystallization behavior of carbon fiber reinforced polyether ether ketone (CF/PEEK) composites under different cooling rates. The characteristic parameters of crystallization were obtained, and the nonisothermal crystallization model was established. The crystallization temperature range of the material at different cooling rates was predicted by the model. The unidirectional laminates were fabricated at different cooling rates in the crystallization temperature range. The results showed that the crystallization temperature range shifted to a lower temperature with the increase of cooling rate, the established nonisothermal crystallization model was consistent with the DSC test results. It is feasible to shorten the cooling control range from the whole process to the crystallization range. The crystallinity and transverse tensile strength declined significantly with the increase of the cooling rate in the crystallization temperature range. The research results provided theoretical support for the selection of cooling conditions and temperature control range, which could be applied to the thermoforming process of semi-crystalline polymer matrixed composites to improve the manufacturing efficiency.

Effects of RE on Critical Cooling Rate of Bearing-B Steel

2012 ◽  
Vol 535-537 ◽  
pp. 761-763 ◽  
Author(s):  
Yi Sheng Zhao ◽  
Xin Ming Zhang ◽  
Zhi Guo Gao
Keyword(s):  
Phase Change ◽  
Cooling Rate ◽  
Experimental Results ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
The Law

The law of phase change of bearing-B steel during continual cooling was studied by adopting dilatometer. The CCT curves of bearing-B steel were drawn, and the effects of RE on critical cooling rates were studied. The experimental results show that the start temperatures of martensite TM was decreased from 438 to 404°C. The critical cooling rate was simultaneously decreased from 33 to 15°C/s.

Effects of the Cooling Rate on the Acoustic Properties of Pb-10Sn Solder

2012 ◽  
Vol 729 ◽  
pp. 356-360
Author(s):  
Endre Harkai ◽  
Tamás Hurtony ◽  
Péter Gordon
Keyword(s):  
Sound Velocity ◽  
Cooling Rate ◽  
Acoustic Microscopy ◽  
Acoustic Properties ◽  
Scanning Acoustic Microscopy ◽  
Cooling Rates ◽  
Reliability Parameters ◽  
Microscopy Characterization ◽  
The Given

Microhardness and sound velocity were measured in case of differently prepared solder samples. The used Pb-10Sn solder samples were melted then cooled down applying different cooling rates. These procedures caused variant microstructure thus different microhardness and sound velocity values. The sound velocity was measured by means of scanning acoustic microscopy. Characterization of solder materials by acoustic microscopy gives the possibility to non-destructively estimate mechanical and reliability parameters of the given material.

The effect of various cooling rates on the membrane ultrastructure of frozen human erythrocytes and its relation to the extent of haemolysis after thawing

1981 ◽  
Vol 49 (1) ◽  
pp. 369-382
Author(s):  
S. Fujikawa
Keyword(s):  
Cooling Rate ◽  
Human Erythrocytes ◽  
Ice Crystals ◽  
Erythrocyte Membranes ◽  
Ultrastructural Changes ◽  
Cooling Rates ◽  
Intracellular Ice ◽  
Frozen State ◽  
Membrane Ultrastructure ◽  
Fast Freezing

Human erythrocytes suspended in buffered isotonic saline were frozen to the temperature of liquid nitrogen at various cooling rates of 3, 140, 700, 1800, 3500, 8000 and 11 500 deg. C/min. The membrane ultrastructure in the frozen state and the extent of haemolysis after thawing were examined at each cooling rate. As the cooling rates increased from 3 to 3500 deg. C/min, the extent of lysis gradually decreased, but further increase in cooling rates in excess of 8000 deg. C/min resulted in an abrupt increase of lysis. Membrane-associated vesicles devoid of intramembrane particles (IMPs) were formed in the erythrocyte membranes frozen at cooling rates slower than 1800 deg. C/min. The frequency and size of these vesicles were highly cooling-rate-dependent and they were no longer formed in the erythrocyte membranes frozen at cooling rates faster than 3500 deg. C/min. Another membrane ultrastructural change associated closely with the formation of intracellular ice crystals appeared at cooling rates faster than 8000 deg. C/min. The membrane regions in direct contact with intracellular ice crystals were physically damaged and had an appearance resembling worm-eaten spots. The erythrocytes frozen at a cooling rate of 3500 deg. C/min exhibited ultrastructural integrity of the membrane by avoiding the membrane changes caused by either slow or fast freezing. It is suggested, from the close relation between membrane ultrastructure and the extent of haemolysis, that the ultrastructural integrity of membrane in the frozen state is important for avoiding haemolysis after thawing, and that the membrane ultrastructural changes caused by both slow and fast freezing were responsible for the lysis after thawing.

Phase Selection in Sub-Rapidly Solidified Au-20Sn Alloys

2015 ◽  
Vol 817 ◽  
pp. 325-330
Author(s):  
Yu Hai Qu ◽  
Kai Jin Yang ◽  
Yan Tian Zhou ◽  
Yong Mao ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Nucleation Theory ◽  
Classical Nucleation Theory ◽  
Copper Mold ◽  
Cooling Rates ◽  
Phase Selection ◽  
Graphite Mold ◽  
Injection Casting ◽  
Rapidly Solidified ◽  
Ausn Phase

The sub-rapidly solidified Au-20Sn eutectic alloys were prepared by four different solidification pathways, such as, graphite mold conventional casting, graphite mold injection casting, copper mold injection casting, and water-cooled copper mold suction casting. The precipitating sequences of competing primary phases of sub-rapidly solidified Au-20Sn alloys with four different cooling rates were investigated. The results show that phase selection process is related to the cooling rates during sub-rapid solidification process. The primary ζ'-Au5Sn phase with developed dendrites precipitate at low cooling rate (2.4×10−4.2×102K/min) and the morphologies of the primary ζ'-Au5Sn change to rosette-like at higher cooling rate (9.0×103K/min). While the cooling rate reaches to 3.5×104K/min, the primary ζ'-Au5Sn phase can be suppressed but δ-AuSn phase will precipitate prior to the ζ'-Au5Sn phase. On the basis of the classical nucleation theory and transient nucleation theory, the process of competitive nucleation between the ζ'-Au5Sn phase and the δ-AuSn phase were analyzed for sub-rapid solidified Au-20Sn alloy. The theoretical calculations are consistent with the experimental investigations.

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